What do you need to know to select the right battery?
Utilisation, voltage, required capacity and discharging time, maximal/minimal dimensions and discharging current (device input)
How do the structure of accumulator plates and density of electrolyte influence capacity and lifetime?
No simple answer can be given, but generally the thicker the plates and the lower the density of electrolyte, the longer the accumulator’s lifetime. At the same time, the higher the density of electrolyte, the higher capacity and the shorter the lifetime.
What prerequisites is the projected accumulator lifetime based on and what is the real usage time?
The proposed (projected) lifetime is based on laboratory-determined discharge and recharge characteristics. The parameters are influenced by the environment in which the battery is operated, and primarily by operating temperatures. The projected lifetime can be achieved in an ideal case only, but in practice, the real lifetime amounts to ca. 70% of the projected lifetime.
How to achieve the maximum battery lifetime?
Keep the battery in optimal operating conditions, i.e. dry environment and constant temperature (ca. 25 °C), comply with the recharging and discharging characteristics, primarily the defined end voltage (minimum battery voltage, when the supplied application is disconnected) and maximum battery voltage after recharge (the voltage at which the recharged will be turned off).
What does it mean when a battery is deeply discharged and what are the consequences for its further usage?
Random deep discharge may occur e.g. when the battery has a lower charge than originally planned, in the case of recharging system fault, repeated discharge without sufficient recharge etc. A fully charged battery is characterised by the full usage of the sulphur acid and electrolyte consisting solely of water. Plate sulphating amounts to the max, significantly raising the battery’s internal resistance, and the water solution in which the battery is placed enables the creation of lead minerals on separators during recharging, potentially leading to internal short circuit on the cell. This type of deep discharge leads to early degradation of the battery and has a major effect on the projected lifetime.
What are the characteristics of Deep Cycle batteries and how do they differ from typical lead acid accumulators?
Deep Cycle batteries are characterised by strong plates and active material with high density. Strong cells support deep storage of reserve energy inside the plate, which is then released during slow discharge. The active material with high density stays longer inside the plates’ grid structures and resists to the usual decline during cyclic conditions. Characteristically, the battery is discharged to the max and the recharged to a significant level again. Deep Cycle batteries are designed for applications that discharge 60-70% of the battery’s capacity.
May a classic battery be used for powering a wheelchair?
A classic battery is not the right option. SLI batteries are used regularly for means of transport, as their electrodes are designed to supply maximum energy over a short of time. Engine starting discharges SLI batteries only from 3% or less. If an SLI battery is used for deep cycle application (e.g. a wheelchair) or means of transport with heavy accessories, the battery’s lifetime is shortened, depending on how deeply and how often it is discharged. Bary Power’s batteries for application with deep discharge use a different chemical substance and milder acid for the production of active electrode paste. This chemical substance enables much longer application operation with deep discharge, with only moderate decline and maximum output.
What is the difference between a gel battery and AGM battery for stationary use (UPS)?
AGM (absorbent glass material) are most frequently used for UPS applications now, primarily thanks to their excellent utilisable value/price ratio. Still, gel batteries have recently become increasingly successful. Silicon gel is the electrolyte in gel batteries, offering higher operating safety and reliability for manipulation. The gel electrolyte offers up to one third longer lifetime, better resistance against vibrations, shorter servicing intervals and longer storage time with lower degree of self-discharge. Due to bigger requirements on internal space, gel batteries have lower capacity and output that AGM batteries of the same size (GEL = 85-90%AGM).